IS_STRING (NoSQL query)

The IS_STRING function returns a boolean value indicating if the type of the specified expression is a string.

An Azure Cosmos DB for NoSQL system function that returns true if the type of the specified expression is a string.

Syntax

IS_STRING(<expr>)

Arguments

Return types

Returns a boolean expression.

Examples

This section contains examples of how to use this query language construct.

Check if value is string

In this example, the IS_STRING function is used to check various values to see if they're a string.

SELECT VALUE {
  isBooleanAString: IS_STRING(true),
  isNumberAString: IS_STRING(1),
  isStringAString: IS_STRING("value"),
  isArrayAString: IS_STRING([ "green", "red", "yellow" ]),
  isNullAString: IS_STRING(null),
  isObjectAString: IS_STRING({ "name": "Tecozow coat" }),
  isObjectStringPropertyAString: IS_STRING({ "name": "Tecozow coat" }.name),
  isObjectBooleanPropertyAString: IS_STRING({ "onSale": false }.onSale),
  isUndefinedAString: IS_STRING({}.category)
}

[
  {
    "isBooleanAString": false,
    "isNumberAString": false,
    "isStringAString": true,
    "isArrayAString": false,
    "isNullAString": false,
    "isObjectAString": false,
    "isObjectStringPropertyAString": true,
    "isObjectBooleanPropertyAString": false,
    "isUndefinedAString": false
  }
]

Remarks

• This function benefits from the use of a range index. For more information, see range indexes.